1. Technical Field
The present invention relates generally to wireless networks; and more particularly to the service of packet data transmissions within such wireless networks at differentiated service quality levels.
2. Related Art
Wireless networks are well known. Cellular wireless networks support wireless communication services in many populated areas of the world. Satellite wireless networks are known to support wireless communication services across most surface areas of the Earth. While wireless networks were initially constructed to service voice communications, they are now called upon to support data communications as well.
The demand for data communication services has exploded with the acceptance and widespread use of the Internet. While data services have historically been serviced via wired connections, wireless users are now demanding that their wireless units also support data communications. Many wireless subscribers now expect to be able to “surf” the Internet, access their email, and perform other data communication activities using their cellular phones, wireless personal data assistants, wirelessly linked notebook computers, and/or other wireless devices. The demand for wireless network data communications will only increase with time. Thus wireless networks are currently being created/modified to service these burgeoning data service demands.
Significant performance issues exist when using a wireless network to service data communications. Wireless networks were initially designed to service the well-defined requirements of voice communications. Generally speaking, voice communications require a sustained bandwidth of approximately 4 kHz with minimum signal-to-noise ratio (SNR) and continuity requirements. Data communications, on the other hand, have very different performance requirements. Data communications are typically bursty, discontinuous, and may require a relatively high bandwidth during their active portions. To understand the difficulties in servicing data communications within a wireless network, consider the structure and operation of a cellular wireless network.
Cellular wireless networks include a “network infrastructure” that wirelessly communicates with mobile stations (MSs) within a respective service coverage area. The network infrastructure typically includes a plurality of base stations dispersed throughout the service coverage area, each of which supports wireless communications within a respective cell (or set of sectors). The base stations couple to base station controllers (BSCs), with each BSC serving a plurality of base stations. Each BSC couples to a mobile switching center (MSC). Each BSC also couples to a corresponding Packet Data Serving Node (PDSN), which also couples to the Internet. The wireless network infrastructure accessed by the PDSN, i.e., a coupled BSC and base stations coupled to the BSC is referred to as the Radio Access Network (RAN). The PDSN is a term specific to the CDMA standards. According to other standards, devices performing similar functions to the PDSN may be referred to as the SGSN and the GGSN (GPRS standard and UMTS standard), for example.
In operation, a MS communicates with one (or more) of the base stations. A BSC coupled to the serving base station routes voice communications between the MSC and the serving base station. The MSC routes the voice communication to another MSC or to the PSTN. BSCs route data communications between a servicing base station and the PDSN. Thus, voice communications and data communications are serviced via different communication paths within the wireless network.
The wireless link between the base station and the MS is defined by one of a plurality of operating standards, e.g., AMPS, TDMA, CDMA, GSM, etc. These operating standards, as well as new 3G and 4G operating standards define the manner in which the wireless link may be allocated, setup, serviced and torn down. These operating standards must set forth operations that will be satisfactory in servicing both voice and data communications. Unfortunately, these operating standards must define such operations in a limited resource environment. The RAN has a maximum set of available resource, e.g., cell/sector bandwidth, communication routing bandwidth, etc. At any given time, all MSs being serviced by the cell/sector must share these RAN resources and must be rationally divided among all serviced MSs (and those requesting service). Any rational division of RAN resources must consider current voice communication demands, current data communication demands, the expected duration of current data communication demands, and the outstanding communications requests, among a number of considerations. Needless to say, this task is daunting.
In most wireless networks, the RAN supports the Transmission Control Protocol/Internet Protocol (TCP/IP) suite of communication protocols. Communications serviced by this protocol suite are typically referred to as “IP communications.” IP communications are packet switched communications, unlike voice communications serviced by the PSTN and many wireless networks, which are circuit switched. An IP network, such as the Internet (and other similar IP communication networks), are networks of data routing switches, communication paths, and interfaces to other networks, e.g., WANs, LANs, the PSTN, wireless networks, etc.
The throughput of any particular path through an IP network, e.g., latency and bandwidth, depends upon switch latency and data path loading. Differing types of IP communications have differing types of performance requirements, e.g., latency, bandwidth, frame error rates, etc. These requirements are generally referred to as IP service quality levels (IP SQL). The IP SQL may be specific, in which particular latencies and bandwidths are required. The IP SQL may also be differential (Diff-Serv, or DS) in which the required level of performance is a particular level of support relative to other levels of support. IP networks provide both of these types of IP SQLs. IP packets typically include an IP SQL indicator in their headers. Each switch or router in the servicing data path processes and routes IP packets based upon their IP SQL indicators.
Because wireless networks are both architecturally and functionally dissimilar to IP networks, no solution exists to provide wireless data communication services with an IP SQL. Currently, the RAN services data communications at a single SQL and provides no differentiation in SQLs. Thus, all IP communications are handled in the same manner by the servicing wireless network, independent of the IP SQL requested for a corresponding data communication.
Thus, there is a need in the art for a system and method that may be employed to coordinate the allocation of RAN resources with the SQL of a serviced data communication.